kern/err.c

   1 /* err.c - error handling routines */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2002,2005,2007,2008  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/err.h>
  21 #include <grub/misc.h>
  22 #include <stdarg.h>
  23
  24 #define GRUB_MAX_ERRMSG         256
  25 #define GRUB_ERROR_STACK_SIZE   10
  26
  27 grub_err_t grub_errno;
  28 char grub_errmsg[GRUB_MAX_ERRMSG];
  29
  30 static struct
  31 {
  32   grub_err_t errno;
  33   char errmsg[GRUB_MAX_ERRMSG];
  34 } grub_error_stack_items[GRUB_ERROR_STACK_SIZE];
  35
  36 static int grub_error_stack_pos;
  37 static int grub_error_stack_assert;
  38
  39 grub_err_t
  40 grub_error (grub_err_t n, const char *fmt, ...)
  41 {
  42   va_list ap;
  43
  44   grub_errno = n;
  45
  46   va_start (ap, fmt);
  47   grub_vsprintf (grub_errmsg, fmt, ap);
  48   va_end (ap);
  49
  50   return n;
  51 }
  52
  53 void
  54 grub_fatal (const char *fmt, ...)
  55 {
  56   va_list ap;
  57
  58   va_start (ap, fmt);
  59   grub_vprintf (fmt, ap);
  60   va_end (ap);
  61
  62   grub_abort ();
  63 }
  64
  65 void
  66 grub_error_push (void)
  67 {
  68   /* Only add items to stack, if there is enough room.  */
  69   if (grub_error_stack_pos < GRUB_ERROR_STACK_SIZE)
  70     {
  71       /* Copy active error message to stack.  */
  72       grub_error_stack_items[grub_error_stack_pos].errno = grub_errno;
  73       grub_memcpy (grub_error_stack_items[grub_error_stack_pos].errmsg,
  74                    grub_errmsg,
  75                    sizeof (grub_errmsg));
  76
  77       /* Advance to next error stack position.  */
  78       grub_error_stack_pos++;
  79     }
  80   else
  81     {
  82       /* There is no room for new error message. Discard new error message
  83          and mark error stack assertion flag.  */
  84       grub_error_stack_assert = 1;
  85     }
  86
  87   /* Allow further operation of other components by resetting
  88      active errno to GRUB_ERR_NONE.  */
  89   grub_errno = GRUB_ERR_NONE;
  90 }
  91
  92 int
  93 grub_error_pop (void)
  94 {
  95   if (grub_error_stack_pos > 0)
  96     {
  97       /* Pop error message from error stack to current active error.  */
  98       grub_error_stack_pos--;
  99
 100       grub_errno = grub_error_stack_items[grub_error_stack_pos].errno;
 101       grub_memcpy (grub_errmsg,
 102                    grub_error_stack_items[grub_error_stack_pos].errmsg,
 103                    sizeof (grub_errmsg));
 104
 105       return 1;
 106     }
 107   else
 108     {
 109       /* There is no more items on error stack, reset to no error state.  */
 110       grub_errno = GRUB_ERR_NONE;
 111
 112       return 0;
 113     }
 114 }
 115
 116 void
 117 grub_print_error (void)
 118 {
 119   /* Print error messages in reverse order. First print active error message
 120      and then empty error stack.  */
 121   do
 122     {
 123       if (grub_errno != GRUB_ERR_NONE)
 124         grub_err_printf ("error: %s\n", grub_errmsg);
 125     }
 126   while (grub_error_pop ());
 127
 128   /* If there was an assert while using error stack, report about it.  */
 129   if (grub_error_stack_assert)
 130     {
 131       grub_err_printf ("assert: error stack overflow detected!\n");
 132       grub_error_stack_assert = 0;
 133     }
 134 }